bug#36494: 27.0.50; [Proposition] New option to scroll up regardless of eob

[Juri Linkov]

> +(defcustom scroll-lock-switch-to-forward-line-at-eob
> +  t
> +  "If set then don't scroll if the end of buffer is visible.")

Please avoid such long names.  A variable name doesn't require
completeness like in a doc string.  scroll-lock-forward-line-at-eob
is enough, or maybe even scroll-lock-at-eob to define behavior
at the end of the buffer - that opens a possibility of adding
more options in the future.